Forced air flow air heating furnace



June 12, 1956 D. F. JONES ET AL 2,749,904

FORCED AIR FLOW AIR HEATING FURNACE Filed Feb. 18, 1952 4 Sheets-Sheet 1FIG. INVENTORS Dom Ff JONES 3; BY KENNETH S. BAssErr A TTOENE Y5.

June 12, 1956 D. F. JONES ET AL 2,749,904

FORCED AIR mow AIR HEATING FURNACE Filed Feb. 18, 1952 4 Sheets-Sheet 2INVENTORS Do/v F do/vEs 6i KENNETH S. BASSETT June .12, 1956 D. F. JONESET AL 2,749,904

FORCED AIR FLOW AIR HEATING FURNACE Filed Feb. 18, 1952 4 Sheets-Sheet smmvrozas DoN F JONES 34 KENNETH 5. BAssETT ATTORNEYJ.

June 12, 1956 D. F. JONES ET AL FORCED AIR FLOW AIR HEATING FURNACEFiled Feb. 18, 1952 4 Sheets-Sheet 4 56 C 47 as INVENTORS DoN F JONES &

KENNETH 3. BAssETT ATTORNEYS.

United States Patent FORCED AIR FLOW AIR HEATING FURNACE Don F. Jonesand Kenneth S. Bassett, Lansing, Mich, as-

signors to Motor Wheel Corporation, Lansing, PVEZCIL, a corporation ofMichigan Application February 18, 1952, Serial No. 272,636

16 Claims. (Cl. 126110) This invention relates to a heater constructionand more particularly to a space heater designed primarily forrelatively small enclosures such as house trailers.

It is an object of this invention to provide a heater or compactconstruction, a heater having one or more insulated side walls so thatit can be positioned directly adjacent a wall or in a corner to therebyreduce to a minimum provided with a cabinet having one or more ofitswalls insulated by a shield spaced from the wall and defining an airchamber between the wall and'the shield. This air chamber not onlyinsulates the wallof the cabinet but also provides an airduct throughwhich outside air may be admitted into the air-circulating system of theheater. The heater cabinet is'furthermore provided with an uprightpartition which divides the cabinet into two chambersrelativelyinsulatecl one from't-he other. In one chamber there ispositioned the burner and-combustion chamber of the heating unit; and inthe other chamber the controls, the blower mechanism, and the fuel tank,

in the casing of a heater which includes :a fuel tank, are

enclosed.

In the drawings: Fig. 1 is a perspective view of the heater. Fig. 2 is aperspective view on an 'enlarged scale of' the heater, portions beingbroken away to better show the construction within the cabinet.

Fig. 3 is a front sectional view of the h'e'ater'taken substantiallyalong the lines 33 in Fig. 4.

Fig. 4 is a fragmentary sectional view of the heater with the oil tankand other parts thereof removed.

Fig. 5 is a fragmentary sectional 'view taken substantially along thelines 5-5 in Fig. 4.

Fig. 6 is a sectional view showing the base of the heater takensubstantially along the lines 6-6in Fig. 4.

The heater shown includes a cabinet 10 supported upon a base 11. Cabinet10 includes side walls 12 and 13, a rear wall 14, and a front wall 15formed with an opening '16 normally closed by a door 17 hinged on thefront wall as at 18 to swing on a vertical axis. The top of the cabinet10 is closed by an imperforate top wall 19. Base '11 is formed as anopen bottomed, rectangular frame having side walls 21 and 22, front andback walls '23 and 24,

respectively, and a top wall 25 which closes and forms a bottom wall forthe lower end of cabinet 10. 'It will be observed that the walls of base11 define an air chamber 26 which is closed at its bottom face bythe'fioor 27 on which the heater is supported.

upon the top wall 25 of base 11.

2,749,904 Patented June 12, 1956 ice Within cabinet 10 there is arrangedan upright partition 28 which divides the interior of the heater cabinetinto two sections or chambers 29 and 30. Within chamber 29 there issupported on the top wall 25 of base 11 a burner and combustion chambercasing 31. Top wall 25 of base 11 has an opening 32 disposed centrallyof casing 31 for admitting outside air in chamber 26 to the burner (notshown) within casing 31. The outside air is preferably admitted tochamber 26 through an opening 33 in floor 27 in which a metal floorflange 34 is arranged. It may be stated at this point that, although anoil heater is shown, it will be appreciated as the description proceedsthat the invention is equally applicable to a heater which utilizes gasas fuel.

The side wall of the heater adjacent the section 30, that is, the sidewall 12, has a louvered opening 36 at the upper end thereof and a secondlouvered opening 37 adjacent the lower end of the cabinet. Likewise, atthe front of the cabinet there is provided a louvered opening 38 nearthe top of the cabinet and another louvered opening 39 at the lowerportion of door 17. Within the cabinet there are arranged three wallshields 4t), 41 and 42. Shield 40 is spaced inwardly of side wall 13.Shield 41 is spaced inwardly of rear wall 14, and shield 42 is spaceddownwardly of top wall 19. Shield 42 is positioned on the upper edges ofshields 40 and 41. The lower edges of shields 40 and 41 are flanged asat 43 and supported It will be observed that partition 28 terminates atits upper end below shield 42 so that chambers 2? and 30 communicate attheir upper ends.

The wall shields 40 and 41 cooperate with walls 13 and .14,respectively, to form an air duct 45 which extends upwardly within theheater cabinet from the base 11 around side wall 13 and rear wall 14. Atone vertical edge the duct 45 is closed by a flange 46, and at its othervertical edge the duct 45 is closed by the end wall piece 47 whichextends between shield 41 and wall 14 (see Fig. '6). At its lower endthe wall duct 45 communicates with thechamber 26 and base 11 through theopenings 48 in wall 25. At its upper end the air duct 45 opens into thespace 49 between top shield 42 and top wall 19.

-minates along a line spaced below shield 42 so that chambers 29 and 30communicate at their upper ends. Within chamber 29there is arranged ablower '52 within a housing 53. The inlet 54 of housing 53 communicateswith a blowerbox '55 which is mounted on shield 41 and partition 28.Blower 52 is driven by a motor 56 which is in turn partially enclosed bya shroud '57. An annular clearance space 58 enables air to be drawn intoblower -52 between shroud 57 and motor 56 to prevent the motorfrombecoming excessively heated.

The wall duct 45 communicates with the interior of the blower box 55through an opening 60 in shield 41. This opening is controlled by adamper 61 pivotaily supported as at 62 and provided with an operatingarm 63. Damper 61 can be positioned to vary the size of opening 60 andthereby control the quantity of air drawn into the blower from duct 45.The interior of blower box '55 also com- Imunicates with the heatchamber 29 through an opening 64 in partition 2.

It will be observed that opening 64 is disposed adjacent shield 41 andthat casing 31 is spaced forwardly of shield 41. Thus, the opening 64-isarranged more or less tangential to the heat section 29 so that-directradiation from casing 31 does not strike the blower, and the blower andmotor are thereby prevented from becoming overheated from suchradiation.

The blower housing 53 has a downwardly opening outlet 65 to which isconnected a warm air duct 66. Duct 66 extends downwardly through chamber39 from outlet 65 to the inlet 67 of plenum chamber 68 which issupported in the cold-air chamber 26 with its inlet 67 projectingupwardly through top wall 25 of base 11. Warm air duct 66 is providedwith a damper 59 and is surrounded by a shield 69 which extends aroundtheduct from the rear shield 41 to a shield 70 on the partition 28.Plenum chamber 68 is formed with a plurality of outlets 72 one of whichopens through front wall 23 of base 11, another through side wall 21 ofbase 11, and another through rear wall 24 of base 11. The outlets 72 inwalls 23 and 21 are provided with louvers 73, and the outlet in the rearwall 24 is closed by a cap 74 which may be removed if it is desired toextend a heat duct from the plenum chamber to a more remote point in theenclosure heated. The bottom wall of plenum chamber 68 is provided witha knock-out disc 75 which may be removed if it is desired to extend aheat duct from the plenum chamber below the supporting floor 27 toanother room in the structure being heated. Plenum chamber 68, it willbe observed, is supported by the side walls of base 11 in spacedrelation to wall 25 and floor 27. Thus, the plenum chamber issubstantially completely surrounded by the cold air in chamber 26.

Within chamber 30 of the cabinet there is also arranged a fuel tank 76which supplies fuel to the burner within casing 31 through afuel-control valve 77. Valve 77 is supported on wall 25 within chamber30 and connects with the burner in casing 31 by means of a fuel line 71.A control rod 7 8 extends from valve 77 upwardly through top wall 19 andis provided with a knob 79 for controlling the rate at which fuel isadmitted to the burner. Below fuel valve 77, wall 25 of base 11 isformed with a trough 80 which extends from a point below fuel valve 77to the opening 32 below casing 31. This drip channel or trough conductsany fuel which might drip from valve 77 to the opening 32 from which itis discharged through the opening 33 in the floor 27 on which the heateris supported. The service cord 81 extends through aligned openings 71 inrear wall 14 and rear shield 41 and is connected to motor 56 through amanual switch 82 mounted on shroud 57 and a thermo switch 83 which ismounted on partition 28 and shield 70. Thermo switch 83 is responsive tothe temperatures within heat chamber 29 to operate the blower. Ifdesired, manual switch 82 may be in the form of a three-way switch toenable the switch to also connect and disconnect the entire electricalcircuit of the heater with the power line with which service cord 81connects. For convenience, there is supported on shield 70 a shut-offstem 84 which can be manipulated within tank 76 for shutting off theflow of fuel to fuel valve 77. Stem 84 has a hooked portion 85 at oneend which, when the stem is inserted through the louvered opening 36 onwall 12, may be engaged with control arm 63 to regulate the position ofdamper 61.

The top wall 25 of base 11 is provided with an opening 87 foraccommodating a fuel line in cases where an outside fuel tank is used inplace of tank 76. Under such circumstances, the fuel line would extendupwardly through the floor 27 and base 11 through opening 87 and connectwith valve 77. A corner partition 88 (Fig. 6) divides the chamberthrough which the outside fuel line passes from the cold air chamber 26of base 11.

Air for combustion is supplied to the burner from chamber 26 into whichcold outside air flows through the floor flange 34. The cold air inchamber 26 also flows through openings 48 upwardly through duct 45 whereit is warmed slightly and travels across the space 49 between top shield42 and top wall 19 and out of the cabinet through the top louvers ofopenings 36 and 38. This continual flow of air through the duct 45 andthe space 49 will maintain walls 13 and 14 relatively cool. Thus, theheater may be positioned directly against a wall or in a corner of thetrailer or other enclosure being heated without subjecting the wall orcorner of the trailer to excessive heating.

The arrangement of the louvered openings on the front and side walls ofthe heater cabinet produces a natural circulation of air upwardlythrough each of the chambers 29 and 30. The air flowing into chamber 29through the lower opening 39 is heated by casing 31 and flows out of thecabinet through upper opening 38. Air flows into chamber 30 throughopening 39 on the door 17 of the cabinet and through opening 37 on theside wall 12 of the cabinet, and this air flows out of the cabinetthrough the openings 38 and 36. There will be substantially no crossflow of heated air from chamber 29 into chamber 30, at least into thatportion of chamber 38 below the upper edge of partition 28. Thus, thetemperature of the fuel tank 76, valve 77, and motor 56 is maintained atan allowable maximum by the shielding around chamber 30, as well as bythe continual circulation of air through this chamber. It will beobserved that shield 70 is spaced from partition 28 and thus provides anair duct between chambers 29 and 30. The shield 70 therefore protectsthe units in chamber 30 from the heat radiated from casing 31. Likewise,the shield 69 forms an air duct around the heat duct 66, thus directingthe heated air around duct 66 upwardly in chamber 30 and away from tank76, valve 77, and motor 56.

In mild weather the natural circulation of air upwardly through thecabinet of the heater may be sufficient to maintain the enclosure at thedesired temperature. If this natural gravity circulation is notsufficient, then blower 52 may be utilized to provide a forced aircirculation. When the motor 56 is in operation, hot air is drawn intothe blower box 55 from heat chamber 29 through opening 64 in partition28. This heated air is directed by blower 52 downwardly through duct 66and into the plenum chamber 68. From the plenum chamber the heated airis directed outwardly across the floor through the louvered openings 73.The provision of the plenum chamber 68 in the base of the heater istherefore desirable not only because it adapts the heater for a morecompact construction but also because it enables discharging the heatedair from the bottom of the heater and outwardly over the floor of thestructure being heated.

It will be observed that the cold outside air never comes into contactwith the heated casing 31. When blower 52 is not operating, the outsideair flows upwardly through duct 45 and outwardly of the cabinet throughthe louvers of openings 36 and 38 above shield 42. When blower 52 isoperating, the outside air flows into the blower where it is mixed withthe room air which flows up and around and is heated by casing 31.

Experience has shown that in small enclosures such as trailers thehumidity often tends to rise to an excessive value. With the heater ofthis invention the humidity within the enclosure being heated can bemaintained at a comfortable value by simply controlling the amount ofoutside air admitted into the circulating air system of the heater, thatis, by controlling the position of damper 61 so as to increase ordecrease the size of opening 60. The cool air flowing into the blowerbox 55 through opening 60, which normally contains less moisture thanthe warmer air within the enclosure being heated, mixes with the hot airflowing into the blower box through opening 64 and is discharged throughthe louvered openings 73.

In warm weather blower 52 can be utilized for bringing fresh air intothe enclosure, thus enabling use of the arrangement as a cooling means.

We claim:

1. In a heater construction, the combination of a cabinet having sidewalls, a heating unit in said cabinet,

means cooperating with at least one of said side walls to form an airduct which is substantially coextensive with said side wall and whichinsulates said one side wall from the heat within said cabinet, and ablower on said cabinet having an inlet connected with said air ductadjacent its upper end, said air duct having an inlet adjacent its lowerend adapted to connect with a source of outside air, said cabinet havinga chamber therein in which said heating unit is located, said chamberhaving an opening adjacent the lower end thereof communicating with thespace immediately surrounding said cabinet, said blower inlet also beingconnected with said chamber, said blower having an outlet communicatingwith the exterior of said cabinet, said blower being arranged to drawair from said chamber and duct and discharge said air exteriorly of saidcabinet, and means adjacent the blower inlet for varying the proportionsof air passing into said blower from said air duct and said chamber.

2. In a heater construction, the combination of a cabinet having sidewalls, a heating unit in said cabinet, a shield within said cabinetspaced inwardly of at least one of said side walls and cooperatingtherewith to form a duct therebetween which insulates said wall from theheat within said cabinet, a blower in said cabinet, said shield havingan opening therein, said blower having an inlet connected with saidopening, said duct having a second opening therein for admitting outsideair to said duct, said cabinet having a heat chamber in which saidheating unit is located, said blower inlet also communicating with saidheat chamber, said blower having an outlet communicating with theexterior of said cabinet, said blower being arranged to draw air fromsaid duct and chamber through said inlet and discharge said airexteriorly of said cabinet, and means adjacent said blower inlet forregulating the proportions of air drawn into said blower from said heatchamber and said duct.

3. The combination set forth in claim 2 wherein said air duct issubstantially coextensive with said side wall.

4. In a heater construction, the combination of a cabinet having sidewalls, a heating unit in said cabinet, a shield within said cabinetspaced inwardly of at least one of said side walls and cooperatingtherewith to form a duct therebetween which insulates said wall from theheat within said cabinet, a blower in said cabinet, said shield havingan opening adjacent its upper end, said blower having an inlet connectedwith said opening, a horizontally disposed partition adjacent the lowerend of the cabinet and defining at the base of the cabinet an airchamber communicating with the lower end of said duct, said air chamberhaving an opening therein adapted to be connected with a source ofoutside air, means defining a plenum chamber within said air chamber,duct means extending downwardly from the outlet of said blower to saidplenum chamber, and means defining an outlet from said plenum chamber tothe exterior of the cabinet.

5. In a heater construction, the combination of a cabinet having sidewalls, a heating unit in said cabinet, a generally vertically extendingair duct adjacent and substantially coextensive with one of the sidewalls of said cabinet, said air duct insulating said one side wall fromthe heat within said cabinet, a blower on said cabinet having an inletconnected with said air duct adjacent its upper end, means adjacent thelower end of the cabinet defining an air chamber communicating with thelower end of said duct and having an opening therein adapted to beconnected with a source of outside air, means defining a plenum chamberwithin said air chamber, the walls of said plenum chamber beinggenerally spaced from the walls of said air chamber so that the plenumchamber is substantially completely surrounded by the outside air insaid air chamber, duct means extending from the outlet of said blower tosaid plenum chamber, and means defining an outlet from said plenumchamber to the exterior of the cabinet.

6. In a heater construction, the combination of a -cabinet having sidewalls, a heating unit in said cabinet, '2). generally verticallyextending air duct adjacent and substantially coextensive with one ofthe side walls of said cabinet, said air duct insulating said one sidewall from the heat within said cabinet, a blower on said cabinet havingan inlet connected with said air duct adjacent its upper end, ahorizontally disposed partition adjacent the lower end of the cabinetand defining at the base of the cabinet an air chamber communicatingwith the lower end of said duct, said air chamber having an openingtherein adapted to be connected with a source of outside air, meansdefining a plenum chamber within said air chamber, the walls of saidplenum chamber being generally spaced from said partition and the wallsof the cabinet at the base thereof so that the plenum chamber issubstantially completely surrounded by the outside air in said airchamber, duct means extending from the outlet of said blower to saidplenum chamber, and means defining an outlet from said plenum chamber tothe exterior of the cabinet.

'7. In a heater construction, the combination of a cabinet having a topwall and side walls, an upright partition in said cabinet dividing-theinterior of the cabinet into two adjacently positioned chambers,insulating shields spaced inwardly of two side walls of the cabinetdefining one of said chambers and cooperating with said two side wallsto form an air duct, an insulating shield spaced downwardly of the topwall of said cabinet and defining a top wall for said chambers, said airduct communicating at its upper end with the space between said topshield and the top wall of the cabinet, a horizontally disposedpartition adjacent the lower end of the cabinet, said last mentionedpartition forming a bottom wall for said chambers and defining an airchamber therebelow, said air chamber being adapted for connection with asource of outside air and communicating with said air duct, and aheating unit in said one chamber, said chambers each having openingsadjacent the upper and lower ends thereof to permit air surrounding thecabinet to circulate upwardly through said chambers, said cabinet havingopenings above said top wall shield providing an outlet for said airduct.

8. The combination set forth in claim 7 including a blower in said otherchamber, said blower having an inlet communicating with said firstmentioned chamber.

9. In a heater construction, the combination of a cabinet having a topwall and side walls, an upright partition in said cabinet dividing theinterior of the cabinet into two adjacently positioned chambers,insulating shields spaced inwardly of two side Walls of the cabinetdefining one of said chambers and cooperating with said two side wallsto form an air duct, an insulating shield spaced downwardly of the topwall of said cabinet and defining a top wall for said chambers, said airduct communicating at its upper end with the space between said topshield and the top wall of the cabinet, a horizontally disposedpartition adjacent the lower end of the cabinet, said last mentionedpartition forming a bottom wall for said chambers and defining an airchamber therebelow, said air chamber being adapted for connection with asource of outside air and communicating with said air duct, a heatingunit in said one chamber, said chambers each having openings adjacentthe upper and lower ends thereof to permit air to circulate upwardlythrough said chambers, said cabinet having openings above said top wallshield providing an outlet for said air duct, a blower in said otherchamber, said blower having an inlet communicating with said firstmentioned chamber, and a plenum chamber in said air chamber below saidhorizontal partition, duct means extending from the outlet of saidblower to said plenum chamber, and means defining an outlet from saidplenum chamber to the exterior of the cabinet.

10. The combination set forth in claim 9 wherein the inlet of said blower also communicates with said air duct adjacent the upper end of thechamber in which said blower is disposed.

11. The combination set forth in claim 10 including means forcontrolling the quantity of air admitted from said air duct to the inletof said blower.

12. In a heater construction, the combination of a cabinet having sidewalls, means cooperating with at least one of said side walls to form anair duct extending vertically in said cabinet which insulates said sideWall from the heat within said cabinet, means defining at the base ofthe cabinet an air chamber having an opening therein adapted to beconnected with a source of outside air, said air duct communicating atits lower end with said air chamber, means defining a heat chamber insaid cabinet, a heating unit in said heat chamber, said heat chamberhaving an inlet opening therein communicating with the space immediatelysurrounding said cabinet, a blower in said cabinet having an inletconnected with said heat chamber and said air duct, said blower havingan outlet communicating with the exterior of said cabinet, said blowerbeing adapted to draw air from said heat chamber and air duct throughsaid blower inlet and discharge said air exteriorly of said cabinet, andmeans adjacent said blower inlet for regulating the relative proportionsof air drawn into said blower from said heat chamber and said air duct.

13. The combination set forth in claim 12 wherein said first mentionedmeans comprises a shield spaced adjacent said side wall of said cabinet,said shield having an opening therein communicating with the inlet ofsaid blower, said last mentioned means comprising means for varying theeffective size of said opening in said shield.

14. In a heater construction, the combination of a cabinet, a heatingunit in said cabinet, a generally vertically extending air duct in saidcabinet, a blower in said cabinet having an inlet connected with saidair duct adjacent its upper end, wall means defining at the base of saidcabinet a generally enclosed air chamber communicating with the lowerend of said air duct, said air chamher having an opening thereincommunicating with the exterior of the cabinet for the admission of airto said air duct and said blower, means defining a plenum chamber withinsaid air chamber, duct means extending downwardly from the outlet ofsaid blower to said plenum chamber, and means defining an outlet fromsaid plenum chamber to the exterior of the cabinet.

15. The combination set forth in claim 14 wherein said cabinet includesa heating chamber in which said heating unit is located, said inlet ofsaid blower also communicating with said heating chamber.

16. The combination set forth in claim 15 wherein said heating chamberis provided with an inlet opening communicating with the exterior ofsaid cabinet.

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